Xiaomi Mi 14T Pro Overheating, Battery Drain and Wi-Fi Issues

I purchased a Xiaomi Mi 14T Pro mobile phone (Serial No: 57314/R4V703154) from the Mi Store online store belonging to Xiaomi Turkey Technology Limited Company on 22 August 2025 for 39,499.00 TL. The device is approximately 3 months old, and since the day of purchase, it has been experiencing serious performance and usage problems. From the first day, the phone shows excessive overheating, frequent freezing and lagging during normal use, and a very rapid decrease in battery health. Even when Wi‑Fi and mobile data are not used during the day, the battery drains extremely fast, and I need to charge the device 2–3 times a day. In addition to these, there are recurring Wi‑Fi and Bluetooth disconnections, which significantly disrupt the continuity of use. Due to these problems, I sent my device twice within one month to Xiaomi Evofone ANKARA Kızılay Technical Service, on 20 November 2025 and 18 December 2025. Both applications were processed under the same service registration number 41845-53021. However, in both visits, the device was returned to me approximately two hours later on the same day with the statement “no problems were found,” without any detailed and comprehensive inspection being carried out, and the issues I reported continued exactly in the same way. Considering that all these problems have existed since the first day and directly affect the basic functions expected from a new phone, I consider my device to be a defective product. I kindly request that the product price be refunded or that my phone be replaced with a faultless equivalent device without any additional cost to me, within the scope of my legal rights and the warranty.